I'd certainly notify PayPal that their service seems to be being used fraudulently. However you might not be eligible for a refund from them.
Quote: "In order for a transaction to be eligible for Buyer Complaint Process review . . .
Your purchase must be a tangible item. Services and intangible items, such as emailed recipes and e-books, are not covered".
Source:
https://www.paypal.com/uk/cgi-bin/webscr?cmd=xpt/Marketing/general/ProtectionsBuyer-outside
So I'd also contact the relevant bank (or card issuer) to see if they can help.
It might also be worth having a word with your local Community Constable to see if he/she thinks that there's any way that the matter can be pursued through the police.
Possibly also of use:
http://www.actionfraud.police.uk/
I can't see that sending Facebook messages would help much. You'll probably just end up getting more and more angry, while the recipient of those messages will simply enjoy laughing at them.